source: src/main/java/negotiator/boaframework/opponentmodel/CUHKFrequencyModelV2.java@ 165

package negotiator.boaframework.opponentmodel;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import genius.core.Bid;
import genius.core.boaframework.NegotiationSession;
import genius.core.boaframework.OpponentModel;
import genius.core.issue.Issue;
import genius.core.issue.IssueDiscrete;
import genius.core.issue.Value;
import genius.core.utility.AdditiveUtilitySpace;
import negotiator.boaframework.opponentmodel.tools.UtilitySpaceAdapter;

/**
 * Optimized version of the ANAC2012 CUKHAgent opponent model. Adapted by Mark
 * Hendrikx to be compatible with the BOA framework.
 *
 * This model keeps track of how many times each value has been offered. In the
 * author's implementation the sum of the value scores is used to quantify the
 * quality of the bid. In my BOA-compatible implementation I divide the sum of
 * the value scores by the maximum possible score to normalize the score to a
 * utility.
 * 
 * Note that after 100 bids the model is no longer updated.
 * 
 * Tim Baarslag, Koen Hindriks, Mark Hendrikx, Alex Dirkzwager and Catholijn M.
 * Jonker. Decoupling Negotiating Agents to Explore the Space of Negotiation
 * Strategies
 *
 * @author Mark Hendrikx
 */
public class CUHKFrequencyModelV2 extends OpponentModel {

        /** History of unique bids, contains at most 100 bids */
        private ArrayList<Bid> bidHistory;
        /**
         * List of Hashmaps storing how much each value has been offered for each
         * issue
         */
        private ArrayList<HashMap<Value, Integer>> opponentBidsStatisticsDiscrete;
        /**
         * Optimization which stores the score of the most prefered value for each
         * issue
         */
        private HashMap<Integer, Integer> maxPreferencePerIssue;
        /**
         * Maximum amount unique bids which may be stored by the agent. After this
         * limit the OM is not updated
         */
        private int maximumBidsStored = 100;
        /** Cache the issues of the domain to improve performance */
        private List<Issue> issues;
        /** Highest possible sum of values */
        private int maxPossibleTotal = 0;
        /**
         * After 100 bids the utilityspace does not chance, and can therefore be
         * cached
         */
        private AdditiveUtilitySpace cache = null;
        /** Boolean which indicates if the utilityspaced is arleady cached */
        private boolean cached = false;

        /**
         * initialization of the model in which the issues are cached and the score
         * keeper for each issue is created.
         */
        @Override
        public void init(NegotiationSession negotiationSession, Map<String, Double> parameters) {
                this.bidHistory = new ArrayList<Bid>();
                opponentBidsStatisticsDiscrete = new ArrayList<HashMap<Value, Integer>>();
                maxPreferencePerIssue = new HashMap<Integer, Integer>();
                this.negotiationSession = negotiationSession;
                try {
                        issues = negotiationSession.getUtilitySpace().getDomain().getIssues();

                        for (int i = 0; i < issues.size(); i++) {
                                IssueDiscrete lIssueDiscrete = (IssueDiscrete) issues.get(i);
                                HashMap<Value, Integer> discreteIssueValuesMap = new HashMap<Value, Integer>();
                                for (int j = 0; j < lIssueDiscrete.getNumberOfValues(); j++) {
                                        Value v = lIssueDiscrete.getValue(j);
                                        discreteIssueValuesMap.put(v, 0);
                                }
                                maxPreferencePerIssue.put(i, 0);
                                opponentBidsStatisticsDiscrete.add(discreteIssueValuesMap);
                        }
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }

        /**
         * This function updates the opponent's Model by calling the
         * updateStatistics method
         */
        public void updateModel(Bid bid, double time) {
                if (this.bidHistory.size() > this.maximumBidsStored) {
                        return;
                }
                if (bidHistory.indexOf(bid) == -1) {
                        this.bidHistory.add(bid);
                }
                if (this.bidHistory.size() <= this.maximumBidsStored) {
                        this.updateStatistics(bid);
                }
        }

        /**
         * This function updates the statistics of the bids that were received from
         * the opponent.
         */
        private void updateStatistics(Bid bidToUpdate) {
                try {
                        // counters for each type of the issues
                        int discreteIndex = 0;
                        for (Issue lIssue : issues) {
                                int issueNum = lIssue.getNumber();
                                Value v = bidToUpdate.getValue(issueNum);
                                if (opponentBidsStatisticsDiscrete == null) {
                                        System.out.println("opponentBidsStatisticsDiscrete is NULL");
                                } else if (opponentBidsStatisticsDiscrete.get(discreteIndex) != null) {
                                        int counterPerValue = opponentBidsStatisticsDiscrete.get(discreteIndex).get(v);
                                        counterPerValue++;
                                        if (counterPerValue > maxPreferencePerIssue.get(discreteIndex)) {
                                                maxPreferencePerIssue.put(discreteIndex, counterPerValue);
                                                maxPossibleTotal++; // must be an increase by 1 one the
                                                                                        // total
                                        }
                                        opponentBidsStatisticsDiscrete.get(discreteIndex).put(v, counterPerValue);
                                }
                                discreteIndex++;
                        }
                } catch (Exception e) {
                        System.out.println("Exception in updateStatistics: " + e.getMessage());
                }
        }

        public double getBidEvaluation(Bid bid) {
                int discreteIndex = 0;
                int totalBidValue = 0;
                try {
                        for (int j = 0; j < issues.size(); j++) {
                                Value v = bid.getValue(issues.get(j).getNumber());
                                if (opponentBidsStatisticsDiscrete == null) {
                                        System.err.println("opponentBidsStatisticsDiscrete is NULL");
                                } else if (opponentBidsStatisticsDiscrete.get(discreteIndex) != null) {
                                        int counterPerValue = opponentBidsStatisticsDiscrete.get(discreteIndex).get(v);
                                        totalBidValue += counterPerValue;
                                }
                                discreteIndex++;
                        }
                } catch (Exception e) {
                        e.printStackTrace();
                }
                if (totalBidValue == 0) {
                        return 0.0;
                }
                return (double) totalBidValue / (double) maxPossibleTotal;
        }

        /**
         * Returns the estimated utilityspace. After 100 unique bids the opponent
         * model is not longer updated, and therefore a cached version can be used.
         */
        public AdditiveUtilitySpace getOpponentUtilitySpace() {
                if (!cached && this.bidHistory.size() >= this.maximumBidsStored) {
                        cached = true;
                        cache = new UtilitySpaceAdapter(this, negotiationSession.getUtilitySpace().getDomain());
                } else if (this.bidHistory.size() < this.maximumBidsStored) {
                        return new UtilitySpaceAdapter(this, negotiationSession.getUtilitySpace().getDomain());
                }
                return cache;
        }

        /**
         * This model does not rely on issue weights. Therefore, the issue weight is
         * uniform.
         */
        public double getWeight(Issue issue) {
                return (1.0 / (double) issues.size());
        }

        public String getName() {
                return "CUHK Frequency Model V2";
        }
}